Alphabet wants Uber to hand over the letter that caused its CEO Travis Kalanick to resign, according to Recode. In June, several Uber investors delivered a letter titled “Moving Uber Forward” to Kalanick. The contents of the letter have not been publicly disclosed, but it was obtained and reviewed by The New York Times. It reportedly said Kalanick must “immediately leave” and the company needs a change in leadership.

Now, Alphabet, which filed a lawsuit against self-driving truck startup Otto and Uber for patent infringement and stealing trade secrets back in February, says the contents of the letter might contain information that could be relevant to the case.

It could potentially help Alphabet determine what Uber knew about the more than 14,000 confidential files that Otto founder and Uber executive Anthony Levandowski allegedly downloaded shortly before he resigned from his job at Google’s Waymo.

Uber, however, responded saying that the letter only “briefly” mentions the suit. “Indeed, the letter contains only a passing reference to this litigation—nothing more, and says nothing about patents or the alleged misappropriation,” according to Uber’s filing.